1. Field of the Invention
The present invention relates to a radio-frequency module which transmits and receives radio-frequency signals of multiple communication bands.
2. Description of the Related Art
Hitherto, various radio-frequency modules which transmit and receive radio-frequency signals of multiple communication bands have been invented. For example, the radio-frequency module disclosed in Japanese Unexamined Patent Application Publication No. 2011-254505 includes a switch IC. An antenna is connected to a common terminal of the switch IC, and plural transmitting-signal input terminals and plural received-signal output terminals are connected to plural selection terminals. In the radio-frequency module disclosed in Japanese Unexamined Patent Application Publication No. 2011-254505, the switch IC performs connection switching control, so that one of the transmitting-signal input terminals or one of the received-signal output terminals can be connected to the antenna.
The radio-frequency module configured as described above is constituted by a multilayer body and mounting circuit devices. The multilayer body is constituted by dielectric layers stacked on each other having circuit patterns formed thereon. The mounting circuit devices are mounted on the multilayer body.
The transmitting-signal input terminals and the received-signal output terminals are realized by external-connecting lands arranged on the back surface of the multilayer body. The switch IC is realized by a mounting circuit device mounted on the front surface of the multilayer body.
Nowadays, there is a growing demand for decreasing the size of a radio-frequency module, such as that configured as described above, and the size of a multilayer body is also decreasing accordingly.
On the other hand, however, as the size of the multilayer body is decreasing, the distance between the external-connecting lands is becoming smaller. Accordingly, the isolation between transmission paths for transmitting plural radio-frequency signals, particularly between a transmission path for transmitting a high-power transmitting signal and another transmission path, is more likely to be decreased.